Device for painting pipes

Abstract

 The invention relates to a device (1) for applying a protective layer, such as a paint layer. The layer must be applied to at least one elongate object (3) for protecting. This object can be a bar or pipe, such as a heating pipe in a glasshouse. The device comprises a frame (10) displaceable along the object. The device further comprises an applicator (7,8) on the frame and oriented toward the object (3) for the purpose of applying the protective layer. The applicator comprises at least two spray nozzles (7,8), each oriented toward the object while enclosing an angle.

Description

[0001] The present invention relates to a device for applying a protective layer, such as a paint layer, to at least one elongate object for protecting, such as a bar or pipe, such as a heating pipe in a glasshouse or in a glasshouse with at least two parallel pipes, sometimes disposed in pairs. According to the known art, such a device comprises a frame displaceable along the object and an applicator on the frame and oriented toward the object for the purpose of applying the protective layer.

[0002] Such a technique is known from US 2,586,256, which shows a device for painting railway tracks. The device comprises a rail vehicle and two applicators, wherein each applicator is directed at one rail of a railway track and comprises two spray nozzles. The spray nozzles are directed at an adjustable angle at the rails.

[0003] The applicator can be based on diverse principles. In by far the most cases, even though this will not always be the case, use will be made of an electrostatic applicator. This is because the pipes or bars or other objects to be protected are usually made from a metal that is highly suitable for electrostatic application. Other methods of applying a protective layer are however by no means precluded, such as to plastic pipes and pipes of alloys, wherein multi-component layers can also be applied for protection purposes.

[0004] Such known devices have various drawbacks. The device from document US 2,586,256 thus comprises a rigid construction. As a result such a known device, which is intended solely for displacement over railway tracks, is substantially or wholly impossible to use in other fields of application. The cost of producing the device can be high in relation to the applicability thereof.

[0005] The present invention has for its object to obviate or at least alleviate the above stated drawbacks of the known art, for which purpose a device according to the present invention has the combination of all features as according to claim 1 and/or 2.

[0006] With a device according to the invention in which an adjusting mechanism is arranged between two applicators and/or supports, the distance therebetween and/or relative to the objects can be adjusted in accordance with the distance between objects that have to be treated or over which the device is displaceable, wherein considerable variations in distance between the objects - other than mere fluctuations from a fixed desired distance - can occur, this without detracting from the applicability of the device according to the invention. This feature makes the device more widely usable. In for instance a field of application for treating heating pipes in glasshouses it is the case that, even within one glasshouse but also from glasshouse to glasshouse, considerable differences can occur in the mutual distance between two adjacent (heating) pipes. This in contrast to the device from document US 2,586,256, which can only be employed on railway tracks with a fixed distance between the rails of the track within a predetermined tolerance or including an allowable fluctuation.

[0007] With an embodiment of a device according to the invention in which a single applicator comprises two spray nozzles, the spray nozzles can enclose an angle in the orientation of each of these spray nozzles toward the object for protecting, a good layer thickness can be realized and a higher treatment speed can also be provided. This layer thickness is preferably as uniform as possible in the length and round the periphery of the objects.

[0008] The present invention finds particular application in situations where two objects for protecting are present which run parallel adjacently of each other. An example hereof is that heating pipes can be arranged parallel to each other in a glasshouse for glass horticulture. In such an application it can be extremely favourable for a second applicator to be arranged on the frame at a lateral distance from the applicator. Both objects for protecting can thus be treated simultaneously. Alternatively, it is however also possible for two pipes to be disposed adjacently of each other. An applicator is oriented toward one of the two pipes or objects, while pretreatment means act on the second of the pipes or objects. One of the two pipes can thus be pretreated, cleaned or a primer can be applied thereto, while the final protective layer is being applied to the other of the two objects using the applicator. The device can also clean both pipes in one operating run and apply the protective layer during the same or a later operating run. In an embodiment with two applicators, it may be possible to arrange an adjusting mechanism therebetween. Setting of the distance therebetween and/or relative to the object can thus be realized. The adjusting mechanism then serves to adapt the device to the intermediate distance between the objects for treating. If two pipes have to be treated, the applicators can be placed at a distance from each other using the adjusting mechanism, this distance corresponding to the intermediate distance between the objects for treating, this being particularly favourable if these objects are heating pipes in a glasshouse for glass horticulture. Use can also be made of a sensor which can be oriented toward an assembly of at least two objects for treating. At least one sensor can be provided per pipe. The sensor can be connected to a control which acts in controlling manner on the adjusting mechanism. A fully automated adjustment of the device to the intermediate distance between two heating pipes or other objects for treating can thus be realized.

[0009] In an additional or alternative embodiment the device can comprise at least one support for placing of the frame on the object. The frame could even travel over the object, which could particularly be the case in applications in a glasshouse for glass horticulture, wherein the frame or the whole device can travel over heating pipes in parallel arrangement. The support then serves for the purpose of placing the frame on the object, which does not alter the fact that a separate carrier can still be arranged for the purpose of displacing the frame of the device if it does not rest on the objects for protecting. Particularly in respect of the support, it can be favourable for the device to support on parallel oriented objects for treating, for which purpose a support and an additional support can then be arranged on the frame with a lateral distance therebetween. It is also the case here that it can be advantageous to arrange at least one sensor on the frame and to orient the sensor toward the assembly of at least two objects when a support and an additional support are arranged for the purpose of supporting on the two objects. The sensor can be connected to a control which can act in controlling manner on the adjusting mechanism so that the supports can also be adjusted, at least in respect of the distance therebetween and the distance between the separate objects for treating.

[0010] In a further additional or alternative embodiment two sub-frames can be provided on the frame for the purpose of arranging thereon an assembly of a support and an applicator. The distance between two objects for treating (heating pipes) can thus be measured or detected in order to adjust the distance between the sub-frames thereon, so that the intermediate distances between the applicators on the one hand and the supports on the other can be readily adjusted to the distance between the objects for treating by means of a single adjustment of the distance between the sub-frames.

[0011] Additionally or alternatively it is possible for at least one applicator to be connected via a lifting mechanism to the frame. Such a measure has the favourable effect that damage to the applicator, or to the objects for protecting, such as heating pipes, can be prevented. If there is a danger of collision, the applicator can be moved clear using the lifting mechanism.

[0012] In a further additional or alternative embodiment it is possible for a carrier, which is for instance height-adjustable using at least one cylinder, to be arranged on the frame for the purpose of displacing the device separately of the object. The carrier can serve to displace the device when it is not in operation for the purpose of applying a protective layer. Conversely, the supports can be used during operation and the height-adjustability of the carrier can be utilized for the purpose of lowering the device onto the objects for treating (heating pipes). Using the height-adjustability of the carrier the device can also be lifted off the heating pipes or other objects for treating and moved away.

[0013] In a further additional or alternative embodiment it is possible for pretreatment means to be arranged on the frame which act on the object for the purpose of pretreatment thereof. Such a pretreatment can comprise of cleaning and/or applying a pretreatment layer, or even a primer. Abrading or brushing treatments can also be performed for a further cleaning effect. If use is made of wet cleaning agents it can moreover also be favourable to generate a drying airflow, and an airflow can also be applied, at a suitable pressure, for the purpose of removing paint residues, dirt and other residues before the protective layer is applied to the object for treating. Drying of the objects can take place using air at lower pressure.

[0014] The device preferably comprises its own drive, which is adjustable depending on the processing of the object. The speed at which the drive propels the device can thus be set subject to a thickness of the protective layer to be applied. Alternatively or additionally, the speed of a pump can also be increased or adjusted in order to realize the desired thickness of the protective layer.

[0015] In an additional or alternative embodiment the device preferably further comprises measuring means for determining the thickness of a protective layer after application thereof. The measuring means can transmit their results to a control which in turn acts on at least one applicator, the drive, the pretreatment means, a pump for pumping to the applicator the medium used to apply the protective layer, and so on. When the thickness of the protective layer has been determined with the measuring means, diverse measures can be taken to modify the pretreatment and/or the application of the protective layer to the end result, so that a good result is always obtained. Alternatively, the measuring means can also be utilized for the purpose of determining the quality of the applied protective layer, for instance by detecting cracks or other shortcomings in an applied protective layer. If such an imperfection is detected, it is possible to have the pretreatment means function with a higher intensity.

[0016] Various aspects, considerations and embodiments of the present invention will be described hereinbelow on the basis of the associated figures, in which the same or similar aspects, components and elements are designated with the same reference numerals, wherein it is noted that the embodiments are in any case given here only by way of illustration and are not limitative, and in which:

figure 1 is a perspective view of a device according to the present invention in operation;

figure 2 shows the device of figure 1 in more detail;

figure 3 shows the same device as in figure 2, but from a different viewpoint;

figure 4 shows a specific embodiment of a device according to the present invention;

figure 5 shows in more detail an applicator according to the present invention in a device;

figure 6 shows the principle of the applicator with two spray nozzles according to the present invention; and

figures 7 and 8 show the operation of a device according to the present invention in respect of variations in the intermediate distances between pipes, such as heating pipes, to which a protective layer has to be applied.

[0017] Fig. 1 shows a device 1 in a glasshouse 2. Running through glasshouse 2 are heating pipes 3 which are connected to a heating system (not shown). Heating pipes 3 are arranged in pairs over floor 4 of glasshouse 2 and rest on brackets 5 which form the basis for carriers 6 on which pipes 3 are arranged. It is the intention, using device 1 according to the present invention, to provide pipes 3 with a protective layer, in particular a paint layer, which can take place using electrostatic application, and wherein for this application a material, such as for instance zinc phosphate, can be used as embodiment of a paint which is or can be electrostatically charged. Other materials can also be applied to pipes 3. Use can even be made of ordinary regular paint which is suitable for and which can withstand the heat of heating pipes. It is then of course necessary to ensure that all the paint is applied to heating pipes 3, for which purpose a correct orientation of the applicators is desired.

[0018] Fig. 2 shows device 1 of fig. 1 in more detail. It can clearly be seen that in device 1 are arranged two applicators 7, 8, each oriented toward one of the pipes 3 for treating. Each of the applicators 7, 8 comprises two spray nozzles 9. Each pair of spray nozzles 9 of one of the applicators 7, 8 encloses an angle. Each spray nozzle 9 is oriented toward one of the pipes 3. Spray nozzles 9 enclosing said angle serves for a good distribution of the basic material for the electrostatic application, the details of which are further dispensed with here as the skilled person in the relevant field is deemed to be aware of the details of electrostatic application. It is important to note here that, for the purpose of electrostatic application to each of the pipes 3, two spray nozzles 9 are used which therefore enclose an angle as already noted above. A better distribution of the material over the periphery of pipes 3 can thus be realized, this material being used, by way of example, for the purpose of electrostatic application.

[0019] Spray nozzles 9, which are oriented per applicator 7, 8 such that they together enclose an angle, are of the type for performing electrostatic application.

[0020] One of the two applicators 7, 8 can be replaced by means for pretreatment, such as a brush, or an air spray nozzle (not shown) or other pretreatment means. A water jet can also be oriented toward the pipes for cleaning purposes. Cleaning agent can also be added here. A combination of two pretreatment means can also be oriented toward each of the pipes 3 shown in fig. 2. In such an embodiment it is possible for the pretreatment means to be arranged in front of applicators 7, 8 in the direction of movement of device 1 in fig. 2.

[0021] In the embodiment of fig. 2 and 3 applicators 7, 8 are arranged on a frame 10 forming the basis of device 1, this on the rear side of frame 10 relative to the direction of movement of device 1 as indicated with arrow A. The device is displaced along pipes 3 in that it supports on pipes 3 by means of travelling rollers 11, which are preferably driven using a drive (not shown). The device can be equipped with sensors for the purpose of measuring a thickness of a protective layer applied by applicators 7, 8 and for the purpose of adjusting the speed of movement of device 1 in the direction of arrow A in accordance with the measured thickness. At a slower speed of movement the layer thickness can be made thicker. Such a sensor will then have to be positioned further to the rear relative to applicators 7, 8 and oriented toward pipes 3.

[0022] Applicators 7, 8 are arranged on frame 10 by means of a hinge construction 12 with which applicators 7, 8 can be folded upward. Applicators 7, 8 can thus be folded upward when the device is displaced in opposite direction to arrow A, for instance during a pretreatment of pipes 3. In such a situation the pretreatment means can also be brought into an active position in the vicinity of pipes 3. The main point of the measure of making applicators 7, 8 foldable upward by means of hinge construction 12 is that damage to pipes 3 and spray nozzles 9 can thus be prevented when spray nozzles 9 are not in operation for the purpose of applying a protective layer to pipes 3.

[0023] A pump 13 is further placed on frame 10. The pump is connected to a supply container 14 in which is stored a material suitable for application of the protective layer. Although use is made here of electrostatic application, the material can also be resin, for instance two-component material. This material is pumped out of supply container 14 using pump 13 and carried to applicators 7, 8, and more particularly the spray nozzles 9 thereof. Pump 13 can be a controllable type of pump to enable setting of the amounts of material from container 14 per unit of time. This is once again associated with the application of a desired thickness of the protective layer to pipes 3. At a higher throughput of the material for the protective layer to spray nozzles 9 and at a constant speed of device 1 in the direction of arrow A a thicker protective layer can be applied, just as when the speed of movement of device 1 in the direction of arrow A is slowed and the pumping speed of pump 13 is constant. An adequate adjustment of the thickness of the protective layer is thus possible and can be very finely controlled, for instance using a control, a display panel 15 of which is shown in combination with an input panel 16. The control forms the heart of the device and controls the speed of movement in the direction of arrow A or in opposite direction, as well as the operation of pump 13.

[0024] Provided under display panel 15 is a space in which a reel 17 can be arranged. A cable can thus be unrolled from reel 17 when device 1 is moved forward. Device 1 can thus be provided with electric power during use, although it is even possible for container 14 to be dispensed with and material for the protective layer on pipes 3 to be supplied from a distance. A platform 18 is further also arranged on which a person can take up position.

[0025] Fig. 2 and 3 further show clearly that rollers 11 are arranged on the one and on the other side of device 1 on a sub-frame 19 together with applicators 7, 8. Two sub-frames 19 are thus arranged on either side of device 1. The purpose of this is shown in fig. 7 and 8. There is a distance between pipes 3 which can vary subject to a specific arrangement in a glasshouse as shown in fig. 1. The distance between rollers 11 is adjustable with an adjusting mechanism 20. Adjusting mechanism 20 comprises a rail 21 and runners 22 movable therealong. In a preferred embodiment a sensor is arranged on the device for the purpose of measuring the distance between pipes 3. The control can then automatically adjust the distance between rollers 11 to the distance between pipes 3. The sensor is not shown in figures, and it is equally possible using the control for manual adjustment of device 1 to take place for the purpose of adjusting the device to the distance between pipes 3. For this purpose a user can enter commands via keyboard 16. A device according to the invention can also support on three or more pipes 3.

[0026] Now that it has been described with reference to fig. 2 that applicators 7, 8 are each associated with one of the sub-frames 19 together with rollers 11 on one side of device 1, it will be apparent that using the setting as elucidated in fig. 7 and 8 the distance between applicators 7, 8 can also be adjusted to the distance between pipes 3, together with the distance between rollers 11 on either side of device 1. This has the advantage that the distance between rollers 11 and the distance between applicators 7 and 8 can be adjusted simultaneously.

[0027] Fig. 6 further shows the manner in which both spray nozzles 9 of a single applicator 7, 8 are oriented toward one of the pipes 3. A sensor can likewise be provided here in order to adapt the configuration of applicator 7, 8 to a detected diameter of pipe 3. It is thus possible to vary the distance between spray nozzles 9 in accordance with a measured pipe diameter. A similar adjustment can be realized by varying the orientation of spray nozzles 9, i.e. the angle enclosed between the spray nozzles can be adjusted. This is an embodiment as shown in fig. 2 wherein spray nozzles 9 of a single applicator 8 can swivel in a horizontal direction. This is therefore an addition or alternative to actually varying the distance between the suspension points of spray nozzles 9. This is because in the embodiment shown in fig. 2 spray nozzles 9 are pivotable about substantially vertical pivot axes running through the suspension points of spray nozzles 9.

[0028] Fig. 4 further shows that pretreatment means can be arranged on device 1. Pretreatment means 23 can comprise a brush 24, in addition to a nozzle 25 for generating an air or water flow, preferably under high pressure, wherein brushes 24 and nozzles 25 are intended to clean pipe 3 as well as possible, or a suitable selection of the above stated pretreatment means. An airflow can serve to dry pipes after they have been cleaned with water or other liquid, optionally with cleaning agent. Pretreatment means 24 can be lowered to pipe 3 or retracted therefrom using a cylinder 26. This can be hydraulic or pneumatic or, alternatively, an electric motor or similar drive can be applied for this purpose. The same applies for the up and downward pivotable applicators 7, 8 as shown in fig. 2 and shown in more detail in fig. 5, which shows a separate cylinder 27 for up and downward pivoting of applicators 7, 8 on a pivot shaft 12.

[0029] Fig. 2 further shows swivel wheels 28. These are arranged under sub-frames 29. Swivel wheels 28 are movable up and downward relative to the frame of device 1 so that the whole device 1 can be placed on swivel wheels 28 at the beginning or the end of a pipe 3. The device can travel over pipes 3 and be positioned for the purpose of being set into operation or, conversely, can be removed from pipes 3 and moved away. A drive can be arranged between the frame of device 1 and swivel wheels 28, and swivel wheels 28 can also be fixed wheels. The drive for extending the swivel wheels 28 can be formed by a cylinder or an electrical drive.

[0030] Many additional and alternative embodiments and possibilities will occur to the skilled person after perusal of the foregoing, all of which lie within the scope of the present invention to the extent that such additional and alternative embodiments do not depart from the letter or spirit of the definitions according to the claims of the present invention. It is thus possible for an electric motor associated with pump 13 to be applied for the purpose of bringing liquid to pressure in a hydraulic system with which the applicators can be pivoted up and downward, or with which the pretreatment means can be pivoted up and downward, or sub-frames 19 can be displaced reciprocally in lateral direction and/or swivel wheels 28 can be displaced or moved up and downward. Instead of an electric power supply, which can be realized by means of the cable on a reel 17, it is also possible to opt for an autonomous system wherein batteries or similar energy sources are applied. It is not an essential prerequisite that sub-frames 19, with one of the applicators 7, 8 and rollers 11 thereon, are provided on one side of device 1. It is also possible for applicators 7 and 8 to be individually oriented toward pipes 3 and not in combination with rollers 11. It can equally well be the case that the whole device comprises no rollers 11 at all, and is displaceable or movable purely and simply over swivel wheels 28, wherein additional measures must then be taken to align the device relative to pipes 3.

Claims

1. Device for applying a protective layer, such as a paint layer, to at least two elongate objects for protecting, such as bars or pipes, such as heating pipes in a glasshouse, comprising:

- a frame displaceable along the objects; and

- at least two applicators on the frame and each oriented toward one of the objects for the purpose of applying the protective layer substantially simultaneously to each of the objects, and with an adjusting mechanism between the applicators for adjusting the distance therebetween and/or relative to the objects.

2. Device for applying a protective layer, such as a paint layer, to at least two elongate objects for protecting, such as bars or pipes, such as heating pipes in a glasshouse, comprising:

- a frame displaceable along the objects;

- at least one applicator on the frame and oriented toward at least one of the objects for the purpose of applying the protective layer to the at least one of the objects; and

- at least two supports, further comprising:

- an adjusting mechanism between the supports for adjusting the distance therebetween.

3. Device as claimed in claim 2, further comprising an additional applicator on the frame at a lateral distance from the applicator.

4. Device as claimed in claim 3, further comprising an adjusting mechanism between the applicator and the additional applicator for the purpose of adjusting the distance therebetween and/or relative to the object.

5. Device as claimed in any of the foregoing claims, further comprising at least one sensor on the frame and oriented toward an assembly of at least two objects, which sensor is connected to a control which acts in controlling manner on the adjusting mechanism.

6. Device as claimed in claim 1, further comprising a support for placing of the frame on at least one of the objects.

7. Device as claimed in claim 6, further comprising an additional support on the frame at a lateral distance from the support.

8. Device as claimed in claim 7, further comprising an adjusting mechanism between the support and the additional support for the purpose of adjusting the distance therebetween.

9. Device as claimed in at least one of the claims 3-4 and at least one of the claims 7-8, wherein an assembly of the applicator and the support is arranged on a first sub-frame and an assembly of the additional applicator and the additional support is arranged on a second sub-frame with a single adjustment mechanism between the first and the second sub-frame.

10. Device as claimed in at least one of the claims 2-9, wherein at least one applicator is connected via a lifting mechanism to the frame.

11. Device as claimed in at least one of the foregoing claims, wherein a carrier, which is for instance height-adjustable using at least one cylinder, is arranged on the frame for the purpose of displacing the device separately of the object.

12. Device as claimed in at least one of the foregoing claims, further comprising pretreatment means on the frame which act on the object for cleaning thereof and/or for applying a pretreatment layer or primer.

13. Device as claimed in at least one of the foregoing claims, further comprising a drive which is adjustable depending on the processing of the object.

14. Device as claimed in at least one of the foregoing claims, further comprising measuring means for determining the thickness of a protective layer after application thereof and which are connected to a control which in turn acts on at least one applicator, the drive, the pretreatment means, a protective layer pump and so on.

Drawing